fix shell setup with lorri

.envrc

@@ -0,0 +1 @@
+eval "$(lorri direnv)"

shell.nix

@@ -1,16 +1,8 @@
-{ pkgs ? import <nixpkgs> {} }:
-
 let
-  easy-dhall = import ./default.nix {
-    inherit pkgs;
-  };
-
-in pkgs.stdenv.mkDerivation {
-  name = "easy-dhall-nix-shell";
-
-  buildInputs = [
-    easy-dhall.dhall-simple
-    easy-dhall.dhall-json-simple
-    easy-dhall.dhall-bash-simple
-  ];
-}
+  pkgs = import <nixpkgs> {};
+  default = import ./default.nix {};
+in
+  pkgs.mkShell {
+    buildInputs =
+      builtins.attrValues default;
+  }